Automotive vehicles are typically constructed using reinforced stamped metal body panels, which combine substantial overall strength and stiffness with a smooth, paintable exterior panel surface. Regarding vehicle hood panels or hoods in particular, panel stiffness is generally satisfied via the combination of a relatively high strength stamped metal outer surface, referred to as an “A-surface”, supported by a series of engine-side or “B-surface” hat-section reinforcements, so named due to the resemblance of such reinforcements to an inverted hat. Such hat-section reinforcements are typically placed between the A-surface and the B-surface of the hood, and include a pair of upper flanges oriented toward the A-surface as well as a single lower flange surface oriented toward the B-surface, with the upper and lower flanges interconnected by a web portion. This conventional hood construction increases the bending stiffness of the hood by placing relatively stiff material, usually stamped steel, as far away as possible from the neutral axis of bending of the hood. However, a hood constructed in this manner may be less than optimal for certain purposes.
For example, in practice hat-section reinforcements are not welded to the customer-visible exterior surface or A-surface of the hood so as to avoid marring the A-surface, i.e., to avoid producing visible flaws in the finished exposed surface of the hood panel. Rather, an inner panel or hood inner is typically attached along the periphery of the outer panel, also known as the hood outer, with either a hemmed flanged mechanical connection or a down-turned and spot-welded flange. The hood inner is typically connected to the hood outer across the expanse of the hood using only a bead of glue or adhesive. As a result, transverse shear stresses resulting from a bending load applied to the hood during normal vehicle travel, such as are continuously imparted to the hood while a vehicle is in motion, may be less than optimally transmitted between the hood outer and the hood inner. Additionally, as hat-section reinforcements are typically stamped from sheet metal having a constant thickness, this geometry may result in under-utilization of material in the web sections, i.e., the interconnecting portions disposed between the upper and lower flanges of the hat-section reinforcement member.